In a video tape recorder or the like, a sliding member such as a tape guide or a head drum for guiding magnetic tape must have a small coefficient of friction with magnetic tape and an excellent abrasion resistance. Aluminum alloys widely adopted as conventional materials for the sliding members such as a head drum, have drawbacks in that they are easy to wear because of their relatively great coefficients of friction and low hardnesses. Therefore, the magnetic tape adheres to the sliding members made of aluminum alloys and may not run smoothly for this reason, or the magnetic tape causes squeaking. These phenomena are notable especially when the magnetic tape is run under the condition of relatively high temperature and humidity.